I've had ME/CFS for decades. Around 10 years ago I got a cold and cough. The cold went but the cough didn't. I'd never cough during the night but as soon as I got up in the morning, and got moving the coughing would start. After some months went to the doctors and he gave me an inhaler. Never did any good whatsoever. I too must of had this cough a couple of years. I went online to look for possible answers. I read something about vitamin D, so got some. Took my first one just before bed. Got up next morning. A miracle. The tickly feeling in my throat had disappeared!! My cough had gone. If only I could find a miracle that simple for my ME/CFS.